This study would objectively assess three gastrointestinal (g.i.) parameters in man: continuous flow, localized transmucosal and surface electrical potentials. Techniques to differentially diagnose various disease states of the stomach and gastroduodenal region would be developed and clinically tested. Continuous flow has not been quantified in the g.i. tract. We propose to develop a flow measurement technique using thermal anemometry. The system will be tested in the dog and eventually assessed in man. The specific studies will measure the continuous flow characteristics of stomach emptying of several standardized liquid test meals. In addition, drugs will be used to enhance or delay stomach emptying. Two types of electrical activity have been recorded from the g.i. tract of man. Disadvantages of present techniques are that surgical intervention is required or the electrodes are placed blindly. The utilization of the fiberoptic gastroscope will permit us to specifically place the recording electrodes. One of the electrical phenomena is the transmucosal potential which is related to mucosal ion secretion. We propose to explore and compare the localized transmucosal potentials of normal mucosa and various lesions, for example, gastric ulcers, cancer and polyps. Surface potentials, generated by smooth muscle, will also be recorded from electrodes placed under direct visualization. We will describe the electric activity of the gastroduodenal junction and explore the state of the g.i. muscle in various disease states. The success of these experiments which characterize continuous flow and two electrical parameters of the g.i. tract should aid in diagnosing several disease entities.